Apparatus for working articles



Jan. 16, 1945; c, MCCAIN 2,367,297

-APPARATUS FOR WORKING ARTICLES Filed Aug. 6, 1943 2 Sheets-Sheet l r 33 A I w A 1 76/ 4/ 32 Y V 43 A; 9' if 60 19 /6 /6 5 r LI //V l/[A C. 6. Ma 64/ Jan. 16, 1945. c. c. M CAIN I 2,367,297

APPARATUS FOR WORKING ARTICLES Filed Aug. 6, 1943 2 Sheets-Sheet 2 7 I'NVf/VTOI? my v 66 5) Z 63 k\ 65 rim/v Patented Jan. 16, 1945 Cecil 0. McCain, Glen Ellyn, 111., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application Augustfi, 1943, Serial No. 497,636

11 Claims This invention relates to an apparatus for working articles and more particularly to an apparatus for slabbing and lapping quartz crystals.

In one stage in the manufacture of quartzcrystals for use as frequency control devices in certain types of electronic communication equipment, it is sometimes the practice to cut the rough quartz blocks into slabs. The cutting operation, which may be performed with a diamond edged saw, may leave a roughened surface on the crystal 7 slab which renders diflicult Optical inspection of the slab to determine the axes or other desired characteristics of the crystal and it is, therefore. usually necessary to lap one side of each slab in order to obtain a suitable plane surface.

Objects of the present invention are toprovide an efficient and effective apparatus for slabbing and lapping quartz crystals. v

In accordance with one embodiment of this in vention, an apparatus may be provided for slabbmg and lapping quartz crystals in which a circular saw is rotatably mounted on an arm which' is, in turn, mounted on a, clutch-driven shaft which is rotatable to engage the saw with the quartz block. A lapping disc is also rotatably mounted on an arm which is mounted on the clutch-driven shaft and after the saw has cut through the crystal block, the disc is moved into engagement with the cut face of the-block to lap the surface thereof. i

Other objects and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the drawings, wherein Y Fig. 1 is a frontelevation of a slabbing appairatus constructed in accordance with this inven- Fig. 2 is a plan view of the same apparatus, partly in section;

Fig. 3 is an end elevation of the same apparatus; Fig. 4 is an enlarged, vertical, sectional view along the line 4-4 of Fig. 3; and,

. Fig. 5 is a vertical, sectional view along the line s .5 of Fig. 4.

One practice in preparing quartz crystal slabs ha been to cut a rough crystal into slabs and thento transfer the slabs to a lapping apparatus wherein the slabs are ground to obtain suitablesurfaces for inspection. Transferring the crystal slabsfrom one apparatus to another involves re- Because of the high degree of.

ing of the crystal slab in boththe cutting and the lapping operations must be done with great care.

By eliminating one positioning operation, a considerable reduction may be effected in the cost of preparing such crystals.

In accordance with the present invention, both the cutting and the lapping operations are successively performed in the same apparatus, thus eliminating the step of transferring the crystal slabs to a lapping apparatus and, as aforesaid,

substantially reducing the operational cost. Re-

ferring to .the drawings, and particularly to Fig. 1, an apparatusfor performing both the slabbing andlapping operations is there illustrated comp-rising a base In on which are mounted two vertically disposed, spaced standards II and I2. A bracket arm I3 is integrally formed with the right standard 12 and extends a short distance to the right thereof, as shown in Fig. 1., Bearings l5 and I6, respectively, are formed in the, upper ends of the standards H and I2, and a shaft I! which extends between these standards is rotatably journalled in these bearings.

'A' sleeve 18 is, mounted on the shaft ll and is' keyed thereto by a pin l9, which extends transversely through both the sleeve and the shaft. This sleeve serves as a rotatable support for a pair of arms 22 and 23 which are rigidly fixed to the left portion thereof and which extend radially therefrom at substantially right angles to each other, as shown in Fig. 3. The outer endsof both of the, arms 22 and 23 are provided with elongated bearings 24 and 25, respectively, in which are iournalled shafts 26 and 21, respectively.

The shaft 26 serves as a rotatable support for a circular saw 30 which is fixed to the right end thereof, while the shaft'zl serves as a rotatable support for a lapping disc 3], also fixed to the right end thereof.

The lapping disc and the saw are rotated by a common belt 32, which passes over pulleys 33 and 34 connected tosthe'left ends of shafts 26 and 21, respectively, and which is driven from a double pulley 35 rotatably mounted on the shaft ll. -A second belt 36 drives the double pulley 35 and may be connected to any suitable power source (not shown). It will be apparent from the foregoing that regardless of the relative angular position of the sleeve Hi, the saw and lapping disc may be rotated on their respective shafts by the belt'32.

In sawing quartz crystals, it may be desirable to provide a certain maximum cuttingpressure in order to prevent damage to either the crystal.

blocker to the cutting tool. In the present apparatus, the cutting pressure is controlled by a spring clutch designated generally at 40. A clutch plate 4| is fixed to the right end of the shaft I! which extends a short distance beyond the bearing 15, the clutch plate being fixed to the shaft H by a set screw 42. Immediately adjacent the clutch plate 4| and engageable therewith in driving relationship is a second clutch plate 43 which is mounted on a short stud shaft 44, and fixed thereto by a set screw 45. The right end of the shaft 44 is journalled in a bearing 46 integrally formed with the upper end of the bracket arm l3, the stud shaft being axially slidable therein as well as rotatable. A pilot pin 4'! extends from the center or axis of the shaft into a cylindrical recess 48 formed in the left end of the stud shaft 44 and provides an auxiliary support for the stud shaft and associated parts The stud shaft 44 is driven by a pulley 53 which is fixed to the right end thereof and around which passes a belt 5| which may be driven by any suitable means (not shown) to obtain a maximum speed of rotation of approximately 12 R. P. M. The clutch plate 43 is normally engaged in driving relationship with the clutch plate 4| by a helically coiled spring 52 which is positioned about the stud shaft 44, one end of the spring bearing against the left side of the bearing 46 while the opposite end of the spring bears against the rear of the clutch plate 43. The spring 52 is selected to provide a contact pressure between the clutch plates which will permit them to slip when a certain predetermined maximum resistance to rotation is encountered.

When it is desired to disengage the clutch plate 43 from the clutch plate 4| to prevent the rotation of the sleeve l8, a ring 55, which is positioned between the pulley 50 and the bearing 46, being mounted on the stud shaft 44 and freely rotatable with respect thereto, is rotated with respect to the bearing 46 to move the clutch plate 43 to the right. This is accomplished by a camming projection 56, which then is moved out of a notch 51 formed in the right side of the bearing 46 and forces the pulley 50 and associated shaft 44 to the right, thus disengaging the clutch plate 43 from the plate 4|. A handle 58 is attached to the ring 55 to facilitate the operation thereof and a stop member 59 mounted on the bearing 46 limits the rotation of the ring 55.

In using this apparatus, a block 60 of quartz is cemented to a supporting plate 6! of glass, or other relatively easily cut material having sufficient rigidity to serve as a support for the crystal block during the slabbing and lapping operations, and the plate is transferred to a platform 62, suitably positioned adjacent the saw and disc, as shown. This platform is pivotally supported on a bolt 63 which is mounted on a bifurcated upper portion 64 of a vertically disposed support 65, the base of which is mounted on a base In of the apparatus. The platform 62 may thus be adjusted so that the saw 35 may cut the crystal block 60 over a range of angles thereto of substantially more than 90. When the platform has been adjusted to the desired position, a nut 65, threaded to the right end of the bolt 63, as

shown in Fig. 5, is tightened to lock the platform in adjusted position.

As may be seen in Figs. 4 and 5, when the plate 5| with the block of quartz cemented to the upper side thereof is placed on the platform 62, the forward portion of the plate rests on a pair of parallel, spaced ways 10 integrally formed with the upper surface of the platform 62 and extending substantially the length thereof. The rear of the plate 6| then rests on three parallel spaced blocks 12 and 13, which are slidably mounted on the upper surface of the platform 62 and which are rigidly joined by a cross plate 14. As shown in Fig. 5, the two side edges of the platform 62 are raised to form longitudinally extending flanges l5 and the two side blocks H and 13 are slidably positioned in the spaces between the ways 73 and the flanges 15. It will be noted that the inner sides of the flanges '15 are bevelled outwardly to receive dovetail portions 15 and fl, respectively, of the blocks H and i3. These dovetail portions aid in maintaining correct alignment of the supporting plate 5! with respect to the platform 62.

The center block "52 is positioned in a semicylindrical recess 89 positioned in the center portion of the platform 62 and extending longitudinally therethrough. This block 12 is provided with a longitudinally extending aperture [H which is internally threaded to receive and engage a threaded rod 82, which is journalled in a support- .ing block 83, rigidly mounted on the rear of platform 52. A collar 84 integrally formed with. the rod 82 bears against the left side of the block 83 while a large knurled nut 85, fixed to the right end of the rod 82, bears against the left side of the block 83, thus holding the shaft in position as well as providing a suitable means for manually rotating the shaft.

After the quartz block and supporting plate 8| have been positioned on the platform 62, as has been described, a clamping plate 85 is placed over the rear portion of the plate 5| and bolted to the slidably mounted blocks H and 73. This clamping plate is preferably made of a relatively re silient material, such as a fibrous material impregnated with a phenolic condensation product, so that, while it may exert considerable clamping force, it will not crush the plate 61, which may be, as aforesaid, made of glass. It will, thus, be apparent that by rotating the threaded rod 82, the quartz block may be moved relatively to the platform 52. A micrometer collar 83 is positioned about the knurled nut 35 and facilitates determination of the amount that the quartz block is advanced by a given rotation of the rod 82.

In operating this apparatus, after the quartz block has been positioned on the platform, as described, the sleeve H3 is rotated by engaging the clutch plate 43 with the clutch plate 4| to en gage the saw 30 with the end of the block. After the saw has cut through the block, leaving thus a substantially fiat surface, the clutch plate 43 is disengaged from the clutch plate 4| and the saw moved in a reverse direction by manually rotating the sleeve l8, by a handle keyed to the left end of the shaft H, to raise the lapping disc 3| above the quartz block 35. The block may then be advanced by rotating the rod 82 as may be required to engage the block with the lapping disc 3| as it is moved downward when the clutch plate 43 is, again engaged in driving relation with the clutch plate 4!. face of the quartz block is then lapped to provide a suitable plane surface for optical inspection,

In the next, and succeeding cycles of operation, slabs of quartz are cut from the block ha ing one side thereof lapped, thus avoiding the necessity of transferring'the slabs to a lapping apparatus to obtain asuitable plane surface.

While but one form of this apparatus has been shown and described, it will be understood that The sawed saw or disc with an article and for applying a predetermined pressure of engagement and means operating coaxially of said pivoting means for rotating said saw and said lapping disc.

2. An article slabbing and lapping apparatus comprising an article support, a rotatable saw, a

rotatable lapping disc, a common rotatable support for the sawand the lapping disc, means for pivoting said rotatable support to engage said saw or disc with an article, rneans operating caxially of said pivoting means for rotating said saw and said lapping disc, and means for applying a predetermined pressure of engagement.

3. An article slabbing and lapping apparatus comprising an article support, a rotatable saw, a

rotatable lapping disc, a common rotatable support for the saw and the lapping disc, means for pivoting said rotatable support to engage said saw or disc with an article, and for applying a predetermined pressure of engagement, means operating coaxially of said pivoting means for rotating said saw and said lapping disc, said saw and said disc operating in substantially the same plane, and means for advancing an article with respect to said operating plane.

4. An article slabbing and lapping apparatus comprising a rotatable support, a pair of arms attached to said support, a saw rotatably mounted on one of said arms, a lapping disc rotatably mounted on the other of said arms, means for rotating said saw and said disc, and means operating coaxially of said saw and disc rotating means for rotating said support to engage the saw or lapping disc with an article with a predetermined pressure of engagement.

5. An article slabbing and lapping apparatus comprising a rotatable support, a pair of arms attached to said support, a saw rotatably mounted on one of said arms, a lapping disc rotatably mounted on the otherof said arms, a' double pulley rotatably mounted on said support, a belt connecting said pulley to said saw and lapping ment, means for .supporting an article adjacent said saw and said lapping disc, and means associated therewith for advancing an article with respect to said saw and said lapping disc.

'7. An apparatus for successively sawing and lapping a quartz crystal block comprising a pivotable support fora crystal block, means on said support for moving a crystal block relatively thereto, a rotatable member adjacent said support, a pair of arms attached to said rotatable member, a saw rotatably mounted on one of said arms, a lapping disc rotatably mounted on the other of said arms, means for rotating said disc and said saw, and means operating coaxially of said saw and disc rotating means for rotating said rotatable support to engage said saw and said lapping disc with the crystal block with a predetermined pressure of engagement.

8. An apparatus for slabbing and lapping quartz crystals comprising a rotatable saw, a rotatable lapping disc, a common support for said saw and said lapping disc, means for rotating said sawand said disc, means operating coaxially of said rotating means for simultaneously addisc, means for rotating said pulley to cause said attached to said support, a saw rotatably mounted on one of said arms, a lapping disc rotatably mounted on the other of said arms, means for rotating said saw and said disc,.means operating coaxially of said rotating means for rotating said support to engage the saw or lapping disc with an article with a predetermined pressure of engage- 9. An apparatus for slabbing and lapping quartz crystals comprising a rotatable saw, a

rotatable lapping disc, a common support for said saw and said lapping disc, means for rotating said saw and said disc, means operating coaxially of said rotating means for simultaneously advancing said saw and said lapping disc in a substantially arcuate path, and for engaging said saw and disc with a crystal with a predetermined pressure of engagement, said saw and said 1apping disc advancing about the same axis, a platform for supporting a quartz crystal, and means associated with said platform for moving a portion of said crystal beyond the edge of said platform and into the path of said saw and said lapping disc.

10. A cutting apparatus comprising a rotary cutting element, a pivotally mounted arm for rotatably supporting said element, means operating coaxially with the pivot of said arm for driving said cutting element, and means coaxial with said driving means for constantly urging said cutting element against the work.

11. A cutting apparatus comprising a rotary cutting element, a, pivotally mounted arm for rotatably supporting said element, means operating coaxially with the pivot of said arm for driving said cutting element, means coaxial with said driving means for constantly urging said cutting element against the work including a constantly driven shaft, and friction means interposed between said shaft and the saw supporting arm.

CECIL C. MCCAIN. 

